1. Field of the Invention
The present invention relates to the field of rock mechanics and geotechnical engineering; and, particularly, to a measurement technology for identifying signs of failure of geotechnical structures using Acoustic Emission (AE) signals generated by a damage in the geotechnical structures and also providing a management standard for failure prediction; and, more particularly, to a method of predicting failure of geotechnical structures using the AE method instead of a conventional displacement or stress measuring method.
2. Description of Related Art
The present invention relates to a measurement technology for identifying signs of failure of geotechnical structures using Acoustic Emission (AE) signals generated by a damage in the geotechnical structures and also providing a management standard for failure prediction, which belongs to the field of rock mechanics and geotechnical engineering. In detail, the present invention relates to a method of predicting failure in geotechnical structures using the AE method instead of a conventional displacement or stress measuring method. Herein, the AE signal is an idea including AE and microseismic (MS) events.
AE is an elastic wave generated when energy of sudden strain relevant to damage of a material is emitted. Generally, generation of the AE signal is sharply increased before macro-failure. As general technologies and equipments for predicting failure in geotechnical structures, today, there are a displacement measuring method using a rod extensometer, an inclinometer probe or GPS; a method of measuring a change in underground water level using a piezometer; and a stress measuring method using a load-meter. Since the strain before failure in geotechnical structures is very small, it is difficult to identify the signs of failure using the conventional displacement or stress measuring method. However, before the failure in the geotechnical structures, microcracks are generated along affixed with minute strain and then the microcracks are grown and coalesced each other, whereby the failure occurs finally. Therefore, if it is possible to detect the microcracks, it is possible to identify the signs of failure. In other words, before the final failure, the microcracks are generated in the geotechnical structures, and the microcracks cannot be detected by the displacement or stress but can be detected by the AE signals.
However, in a measurement apparatus affixed with an AE sensor for predicting failure in geotechnical structures using AE signals, since attenuation of the AE signals is occurred necessarily, it is difficult to obtain generalized parameters for predicting the failure in the geotechnical structures from the AE signals detected by the AE sensors that are respectively positioned at a difference place.
Further, since the ground constituting the geotechnical structures is comprised of rocks and soils and thus the AE signals generated at each area of the ground are not the same as each other, it is difficult to obtain the generalized parameters for predicting the failure in the geotechnical structures.